Re: [PATCH v1 03/11] perf: Allow for multiple ring buffers per event

Alexander Shishkin
2014-05-08T12:46:42Z

Peter Zijlstra <peterz@infradead.org> writes:

> On Thu, May 08, 2014 at 03:34:17PM +0300, Alexander Shishkin wrote:
>> Peter Zijlstra <peterz@infradead.org> writes:
>>
>> > So the aux_head/tail values should also be in the file space and not
>> > start at 0 again, similar for the offsets in the AUX record.
>>
>> Thinking some more about it: if we keep aux_{offset,size} in userpg,
>> then it would make sense to have aux_{head,tail} run from 0 to infinity
>> similar to data_{head,tail}, especially considering that neither data_*
>> nor aux_* pointers are file offsets anyway.
>
> Yeah, this might make it easier. So then the rule is *_offset +
> *_{head,tail} is the actual file offset into the buffer.

You mean *_offset + (*_{head,tail} % *_size) ?

Regards,
--
Alex